The present invention relates to a method for checking and/or calibrating a vertical axis of a rotating laser.
Rotating lasers are used indoors and outdoors for leveling and marking tasks, such as displaying laser markings running horizontally, vertically, or diagonally on a target surface, or determining and checking horizontal heights, perpendicular lines, alignments, and plumb points. Rotating lasers can be arranged in various device positions, which are designed as horizontal positions and vertical positions. One thereby differentiates between horizontally usable rotating lasers, which are solely used in the horizontal position, and horizontally and vertically usable rotating lasers, which are used in the horizontal position and the vertical position. Horizontally usable rotating lasers have as device axes a first horizontal axis and a second horizontal axis, which run perpendicular to each other and span a horizontal plane. Horizontally and vertically usable rotating lasers have as a device axis, in addition to the first and second horizontal axes, a vertical axis that runs perpendicular to the horizontal plane of the first and second horizontal axes.
To ensure the accuracy of a rotating laser when in operation, the accuracy must be checked regularly and if a maximum difference defined by the device manufacturer is exceeded, the rotating laser must be calibrated. The accuracy of the rotating laser is thereby checked for every device axis. Methods are known for checking and/or calibrating a horizontal axis and for checking and/or calibrating a vertical axis. For horizontally usable rotating lasers, the first and second horizontal axes are checked sequentially, wherein the sequence is arbitrary. For horizontally and vertically usable rotating lasers, after the first and second horizontal axes are checked, a check of the vertical axis is performed.
The orientation of the device axes in a defined state occurs by means of a leveling device of the rotating laser. The defined state of the rotating laser in the horizontal position is referred to as the horizontal state and in the vertical position as the vertical state. The leveling device comprises a first leveling unit that orients the first horizontal axis in a first defined state, a second leveling unit that orients the second horizontal axis in a second defined state, and for a vertically usable rotating laser, there is a third leveling unit that orients the vertical axis in a third defined state. Each of the leveling units comprises an inclination sensor that measures the inclination of the device axis, and an adjustment element with which the inclination of the device axis can be adjusted. Ideally, the inclination sensors are oriented parallel to the allocated device axes. If an inclination sensor is not parallel to the allocated device axis, the device axis will have an inclination error.
In the operating instructions of their rotating lasers, the device manufacturers of horizontally and vertically usable rotating lasers define methods for checking the vertical axis, which are to be performed regularly by the operator, and methods for calibrating the vertical axis, which are to be performed regularly by the operator, if the established maximum difference for the vertical axis is exceeded. The known methods for checking and/or calibrating a vertical axis are performed in the vertical position of the rotating laser. The rotating lasers are set up on a stable substrate or on a tripod at a measurement distance to a measuring surface. Every device manufacturer defines the measurement distance between the rotating laser and the measuring surface and establishes a maximum difference for the vertical axis.
In regard to the LAR-250 rotating laser by Stabila, the rotating laser is mounted on a tripod and can be adjusted about a rotary axis of the tripod. The LAR-250 rotating laser produces a first laser beam rotating about an axis of rotation and a stationary second laser beam that runs perpendicular to the laser plane of the rotating first laser beam; the vertical axis is checked using the stationary second laser beam. The vertical axis is checked between a first measuring surface and a parallel second measuring surface, which are at a distance of at least 10 m to each other. The LAR-250 rotating laser is set up in a first spatial position directly in front of the first measuring surface and in a second spatial position directly in front of the second measuring surface. A reversal measurement takes place in the spatial positions, wherein the LAR-250 rotating laser is oriented manually or using an automatic rotary platform in the angular positions. In the first spatial position, the LAR-250 rotating laser is rotated into a first angular position, in which the vertical axis is oriented toward the first measuring surface, and the device axes are oriented in the vertical state. The incident position of the second laser beam on the first measuring surface is marked as the first control point. The LAR-250 rotating laser is rotated by 180° about the axis of rotation of the tripod into a second angular position, in which the vertical axis is oriented, in the axis direction opposite to the first angular position, to the first measuring surface, and the incident position of the second laser beam on the second measuring surface is marked as the second control point. The LAR-250 rotating laser is positioned along the vertical axis from the first spatial position into the second spatial position, and device axes of the LAR-250 rotating laser are oriented in the vertical state. The height of the LAR-250 rotating laser is adjusted using the height adjustment device of the tripod until the incident position of the second laser beam on the second measuring surface coincides with the second control point. The LAR-250 rotating laser is rotated 180° about the axis of rotation of the tripod and the incident position of the second laser beam on the first measuring surface is marked as a third control point. The distance between the first and third control points is calculated as a difference, which is compared against the maximum difference of 2 mm for the vertical axis, as calculated by Stabila. If the difference is greater than the maximum difference, calibration of the vertical axis is required. The vertical axis is calibrated using the first and third control points. The LAR-250 rotating laser is adjusted using the leveling device until the stationary second laser beam is arranged centrally between the first and third control points. This position of the stationary second laser beam is stored as the new reference value or new zero position for the vertical state of the vertical axis.
In regard to the GRL 500 HV rotating laser by Bosch Power Tools, the vertical axis is checked using a plumb line, and calibrated if required. The GRL 500 HV rotating laser produces a rotating first laser beam and a stationary second laser beam, which runs perpendicular to the laser plane of the rotating first laser beam; the vertical axis is checked using the rotating first laser beam. For the GRL 500 HV rotating laser, Bosch Power Tools established a measurement distance of 10 m to the measuring surface and a measuring surface height of 10 m. Using the plumb line, the operator draws a perpendicular comparison line on the measuring surface and compares the vertical laser plane, which the rotating first laser beam generates, against the perpendicular comparison line. The laser beam is adjusted using the leveling device of the rotating laser in such a manner that the rotating first laser beam centrally strikes the plumb line at the upper end of the measuring surface. The incident position of the rotating first laser beam is marked as a control point on the measuring surface and the distance between the control point and the perpendicular comparison line is calculated as a difference.
The difference is compared against the maximum difference of 1 mm established by Bosch Power Tools for the vertical axis. If the difference is greater than the maximum difference, calibration of the vertical axis is required.
On the GRL 500 HV rotating laser, the vertical axis is calibrated in a separate procedure conducted after the method for checking the vertical axis. For calibrating the vertical axis, Bosch Power Tools established a measurement distance between 5 m and 10 m to the measuring surface and a measuring surface height of 10 m. Using the plumb line, the operator draws a perpendicular comparison line on the measuring surface. The tripod is oriented in such a manner that the rotating first laser beam crosses the perpendicular comparison line. The first laser beam is adjusted using the leveling device until the laser plane spanning the rotating first laser beam is arranged as parallel as possible to the perpendicular comparison line. If no congruence is achieved between the rotating first laser beam and the perpendicular comparison line, the method steps (orienting tripod, leveling rotating laser, and adjusting laser beam using the leveling device) are repeated. When congruency is achieved between the rotary first laser beam and the perpendicular comparison line, the adjustment of the leveling device is stored as a new reference value or new zero position for the vertical axis. After calibration, an additional loop is provided for checking the vertical axis for inclination error. If the difference lies within the maximum difference, the GRL 500 HV rotating laser may be operated with the specified accuracy when handled properly. If the difference lies outside the maximum difference, the GRL 500 HV rotating laser must be adjusted by the device manufacturer.
In regard to the TRIAX UL-300 rotating laser by Sokkia, the vertical axis is also checked using a plumb line and calibrated, if necessary. The TRIAX UL-300 rotating laser produces a rotating first laser beam and a stationary second laser beam, which runs perpendicular to the laser plane of the first laser beam; the vertical axis is checked using the rotating first laser beam. For the TRIAX UL-300 rotating laser, Sokkia established a measurement distance of 6 m to the measuring surface and a measuring surface height of at least 2.5 m. Using a plumb line, the operator draws a perpendicular comparison line on the measuring surface and compares the vertical laser plane generated by the rotating first laser beam against the perpendicular comparison line. If the first laser beam is distorted, calibration of the vertical axis is required. The vertical axis can be calibrated using a rotating laser beam (first laser beam in the rotating mode) or a laser beam moving back and forth (first laser beam in line mode). The laser beam is adjusted using the leveling device until the marking generated by the laser beam on the measuring surface is vertical and congruent with the perpendicular comparison line. When congruency is achieved between the laser beam and the perpendicular comparison line, the adjustment of the leveling device is stored as a new reference value or new zero position for the vertical state of the vertical axis.
The known methods for checking and/or calibrating a vertical axis are prone to error and not suited for automation. The method provided by the Stabila LAR-250 rotating laser for checking and calibrating the vertical axis is dependent on the care and accuracy with which the operator marks the incident positions of the laser beam as control points on the measuring surface. It is also disadvantageous in that the operator must perform measurements at two different spatial positions and must also move the LAR-250 rotating laser. The methods provided by the Bosch Power Tools GRL 500 HV for checking and calibrating a vertical axis using a plumb line have the disadvantage of an unusual measurement environment. For checking and calibrating the vertical axis, Bosch Power Tools requires a measuring surface having a height of 10 m. For many measuring tasks inside, there are no measuring surfaces having a height of 10 m. In addition, it may be very awkward for an operator to attach a plumb line at a height of 10 m. The method provided by the Sokkia TRIAX UL300 rotating laser for checking and calibrating a vertical axis using a plumb line depends on the assessment of the operators when they see the marking produced by the rotating first laser beam on the measuring surface as being distorted and the method does not contain any quantitative criterion by means of which operators can decide whether calibration of the vertical axis is required.
The object of the present invention consists of developing a method for checking and/or calibrating a vertical axis of a rotating laser with a high degree of accuracy. In addition, the method is to be adaptable to the respective ambient conditions of the measurement environment and be suitable for automated execution.
According to the invention, the method for checking and/or calibrating a vertical axis of a rotating laser, which projects a first laser beam that is rotatable about an axis of rotation and a stationary second laser beam, comprises the steps:                The rotating laser is positioned at a measurement distance Dv to a laser receiver, wherein the rotating laser is oriented in the vertical position and the laser receiver is oriented in a transverse arrangement,        The device axes of the rotating laser, which are designed as the first horizontal axis, the second horizontal axis, and a vertical axis, are oriented in a defined state, wherein the defined state is established by a first zero position for the first horizontal axis, a second zero position for the second horizontal axis, and a third zero position for the vertical axis,        The rotating laser is arranged in a first angular position, wherein the vertical axis is oriented in the first angular position on a detection field of the laser receiver,        The incident position of the second laser beam on the detection field of the laser receiver is defined as a first control point and the distance of the first control point to a zero position of the detection field is stored as the first height offset,        The rotating laser is arranged in a second angular position, wherein the second angular position is rotated by 180° to the first angular position about the axis of rotation of the rotating laser.        The incident position of the second laser beam on the detection field of the laser receiver is defined as the second control point and the distance of the second control point to the zero position of the detection field is stored as a second height offset,        The distance between the first control point and the second control point is calculated as difference Δ from the first and second height offsets,        The measurement distance Dv between the rotating laser and the laser receiver is determined, and        The difference Δ is compared against a maximum difference Δmax.        
In regard to the method according to the invention for checking and/or calibrating a vertical axis, the measurement distance between the rotating laser and the laser receiver is measured and is not set to a predetermined measurement distance. This has the advantage that the measurement distance can be adapted to the ambient conditions of the measurement environment. In the method according to the invention, the method step, in which the measurement distance is determined between the rotating laser and the laser receiver, can be executed at various locations. In the method according to the invention, the incident positions of the laser beam are determined using a laser receiver and stored as height offsets to the zero position of the detection field. By using a laser receiver with a measurement function, the measurement accuracy is increased in executing the method. The laser receiver determines the incident position of the laser beam on the detection field according to a fixed routine.
This has the advantage that the accuracy of the method is independent of the care taken by the operator and is suited for the automated execution of the method. When the rotating laser is arranged on a motorized rotating platform, the method according to the invention can be conducted in a fully automated manner. In a semi-automatic design, the operator manually arranges the rotating laser into the first and second angular positions upon request; all other method steps are carried out by the rotating laser and laser receiver.
Preferably, the measurement distance between the rotating laser and the laser receiver is determined by means of the second laser beam and the laser receiver. The method according to the invention has the advantage that the ambient conditions of the measurement environment can be taken into account when checking and/or calibrating the vertical axis, and that furthermore no additional device components are required. The measurement distance between the rotating laser and the laser receiver is selected as permitted by the measurement environment.
In a particularly preferred manner, the measurement distance between the rotating laser and the laser receiver is determined as a first distance by means of a first measuring procedure, as a second distance by means of a second measuring procedure, or as a distance averaged from the first and second distances. If the measurement distance between the rotating laser and the laser receiver can be determined by means of various measuring procedures, the method for checking and/or calibrating a vertical axis can be adapted to the ambient conditions of the measurement environment and the functions of the measuring devices (rotating laser and laser receiver).
In a first preferred embodiment, the measurement distance between the rotating laser and the laser receiver is determined as a first distance by means of the first measuring procedure. In the first measuring procedure, the laser beam is inclined by an inclination angle and the distance of the inclined laser beam to the zero position of the detection field is stored. The first measuring procedure is suited for laser receivers with a measuring function, which can measure the distance of a laser beam to a zero position as a height offset. In the method according to the invention, the measurement of the first distance may occur in the first angular position or the second angular position. The inclination of the laser beam by the inclination angle may be performed by means of the leveling device of the rotating laser. The leveling device comprises a first leveling unit that orients the first horizontal axis in a first defined state, a second leveling unit that orients the second horizontal axis in a second defined state, and a third leveling unit that orients the vertical axis in a third defined state.
The rotating laser may be arranged in an arbitrary first angular position; one must only ensure that the vertical axis is oriented toward the detection field of the laser receiver. If the measurement distance between the rotating laser and the laser receiver is determined as a first distance by means of the first measuring procedure, the inclination of the laser beam must be measurable from the detection field as a height offset. Therefore, it is advantageous if the first or second horizontal axis of the rotating laser is oriented parallel to a longitudinal direction of the detection field. If the first horizontal axis is oriented parallel to the longitudinal direction of the detection field, the laser beam will be inclined by means of the first leveling unit about the second horizontal axis, wherein the adjustment of the inclination angle occurs by means of a first adjusting element and a first inclination sensor of the first leveling unit. When the second horizontal axis is oriented parallel to the longitudinal direction of the detection field, the laser beam will be inclined by means of the second leveling unit about the first horizontal axis, wherein the adjustment of the inclination angle occurs by means of a second adjusting element and a second inclination sensor of the second leveling unit.
In a first variant of the first measuring procedure, the rotating laser is oriented vertically, the vertically oriented laser beam is set to the zero position of the detection field, the laser beam is inclined toward the laser receiver by an inclination angle α, the incident position of the inclined laser beam on the detection field of the laser receiver is determined as a first measuring point, the distance of the first measuring point to the zero position of the detection field is stored as first height h1=h(α) and the first distance d1 is calculated from the inclination angle α and a height difference Δh between the first height h1 and the zero position of the detection field. When the transverse direction of the laser receiver is oriented parallel to the direction of gravity, the first distance d1 can be calculated according to the formula tan(α)=Δh/d1. For small inclination angles α, tan(α)≈ sin(α) approximately. The first variant of the first measuring procedure is particularly suited for rotating lasers and laser receivers with an auto-alignment function, in which the height adjustment of the laser beam to the zero position of the detection field of the laser receiver can be performed automatically.
In a second variant of the first measuring procedure, the rotating laser is oriented vertically, the incident position of the vertically oriented laser beam on the detection field of the laser receiver is determined as a reference point, the distance of the reference point to the zero position of the detection field is stored as reference height h0=h(0°), the laser beam is inclined by inclination angle α, the incident position of the inclined laser beam on the detection field is determined as a first measuring point, the distance of the first measuring point to the zero position of the detection field is stored as first height h1=h(α) and the first distance d1 is calculated form the inclination angle α and a height difference Δh between the first height and the reference height. When the transverse direction of the laser receiver is oriented parallel to the direction of gravity, the first distance d1 can be calculated according to the formula tan(α)=(h1−h0)/d1=Δh/d1. For small inclination angles α, tan(α)≈ sin(α) approximately. The second variant of the first measuring procedure is suited for rotating lasers and laser receivers without an auto-alignment function. The operator must only ensure that the laser beam inclined at inclination angle α is captured by the detection field of the laser receiver. For a rotating laser and laser receiver with an auto-alignment function, the laser beam is automatically moved to the region of the detection field.
In a third variant of the first measuring procedure, the rotating laser is oriented vertically, the vertically oriented laser beam is inclined in an inclination direction by inclination angle α, the incident position of the inclined laser beam on the detection field of the laser receiver is determined as the first measuring point, the distance of the first measuring point to the zero position of the detection field is stored as first height h1=h(α), the laser beam is inclined in an opposing inclination direction by a negative inclination angle −α, the incident position of the inclined laser beam on the detection field is determined as the second measuring point, the distance of the second measuring point to the zero position of the detection field is stored as second height h2=h(−α) and the first distance (d1) is calculated from the inclination angle α and a height difference Δh between the first height and the second height. When the transverse direction of the laser receiver is oriented parallel to the direction of gravity, the first distance d1 can be calculated according to the formula tan(2α)=(h(α)−h(−α))/d1=Δh/d1. For small inclination angles α, tan(2α)≈ sin(2α) approximately. The third variant of the first measuring procedure is suitable for rotating lasers and laser receivers with and without an auto-alignment function. When the laser beam is initially oriented to the zero position of the detection field or at least in the vicinity of the zero position, the entire detection height of the detection field can be used. For a device system with an auto-alignment function, the adjustment to the zero position can be performed automatically.
In a second preferred embodiment, the measurement distance between the rotation laser and the laser receiver is determined as the second distance by means of the second measuring procedure. In the second measuring procedure, the rotating laser is oriented vertically, the laser beam is moved at a known speed vR, the signal length ts of the laser beam on the detection field of the laser receiver is determined and the second distance d2 is calculated from the speed vR, signal length ts and detection width BD of the detection field. When the transverse direction of the laser receiver is oriented parallel to the direction of gravity, the second distance d2 can be calculated according to the formula ts/tfull=BD/(2πd2), where tfull=60/vR. Speed vR is indicated in revolutions per minute and time tfull required for one revolution is 60/vR. The second measuring procedure is suitable for rotation lasers and laser receivers without an auto-alignment function. The laser receiver must be able to measure signal length ts of the laser beam on the detection field.
In a third preferred embodiment, the measurement distance between the rotating laser and the laser receiver is determined as the distance averaged from the first and second distances. By averaging the first and second distances, the accuracy with which one can determine the measurement distance between the rotating laser and the laser receiver, can be increased. The first distance, which is determined using the first measuring procedure, is greater than or equal to the actual measurement distance. When the transverse direction of the laser receiver is not oriented parallel to the direction of gravity but is inclined in relation to the direction of gravity, the horizontal distance perpendicular to the direction of gravity is less than the distance, which the detection field of the laser receiver measured. The second distance, which is determined using the second measuring procedure, is less than or equal to the actual measurement distance. When the transverse direction of the laser receiver is not oriented parallel to the direction of gravity but is inclined in relation to the direction of gravity, the vertical distance in the direction of gravity, which the laser beam passes over on the detection field, is greater than detection width BD of the detection field.
In a preferred development of the method, an inclination of the laser receiver relative to a direction of gravity is determined as a first vertical angle φ1 in a first vertical plane and/or as a second vertical angle φ2 in a second vertical plane, wherein the vertical plane is spanned by the direction of gravity and a perpendicular vector of the detection field of the laser receiver and the second vertical plane is spanned by a longitudinal direction and a transverse direction of the detection field. The first vertical angle φ1 is measured between the perpendicular vector of the detection field and the direction of gravity, wherein the first vertical angle φ1 represents the deviation of 90° between the perpendicular vector and the direction of gravity, and the second vertical angle φ2 is measured between the direction of gravity and the longitudinal direction of the detection field. In executing the method according to the invention, the laser receiver is oriented in a transverse arrangement, wherein the longitudinal direction of the detection field should run perpendicular to the direction of gravity and the transverse direction of the detection field should run parallel to the direction of gravity. By inclining the laser receiver relative to the direction of gravity, the horizontal and vertical distances deviate from the distances that the detection field of the laser receiver measured. If the inclination of the laser receiver is known, the dimensions can be corrected accordingly. The laser receiver may be inclined relative to the direction of gravity by the first and/or second vertical angle. The inclination of the laser receiver can be measured by means of a 2-axis acceleration sensor or by means of two 1-axis acceleration sensors.
In a particularly preferred manner, in the evaluation with the laser receiver for the first vertical angle φ1 and/or the second vertical angle φ2, an angle-dependent correction factor cos(90°−φ1), cos(90°−φ2), 1/cos(90°−φ2) is multiplied. By the multiplication with an angle-dependent correction factor or with multiple angle-dependent correction factors, the inclination of the laser receiver can be compensated by the first vertical angle φ1 and/or the second vertical angle φ2. In the formulas that use the measuring function of the laser receiver and measure distances on the detection field in the longitudinal direction, the distances are multiplied by a correction factor cos(90°−φ1)=sin(φ1) for the first vertical angle φ1 and a correction factor cos(90°−φ2)=sin(φ2) for the second vertical angle φ2. The correction factor cos(90°−φ1)*cos(90°−φ2)=sin(φ1)*sin(φ2) is to be taken into account in the distance measurement of the measurement distance using the first measuring procedure, in determining the difference between the first and second control points, and calculating the correction angle within the scope of the method according to the invention. In regard to the distance measurement of measurement distance Dv as the second distance using the second measuring procedure, one does not use the conventional measuring function of the laser receiver in the longitudinal direction, but one uses the detection width in the transverse direction. By inclining the laser receiver in the second vertical plane by second vertical angle φ2, the vertical distance that the laser beam passes over in the detection field is greater than the detection width BD of the detection field. The signal length of the laser beam corresponds to the vertical distance in the detection field. For the vertical distance, the correlation BD/cos(90°−φ2)=BD/sin(φ2) applies. An inclination of the laser receiver by the first vertical angle φ1 does not change the vertical distance. The angle-dependent correction factor 1/cos(90°−φ2)=1/sin(φ2) is taken into account in the distance measurement using the second measuring procedure.
In a preferred development of the method, for orienting the vertical axis in the defined state, multiple zero positions are included as a function of a temperature or a temperature-dependent measured value and stored in a characteristic curve. The term “characteristic curve” thereby comprises both a continuous characteristic curve as well as a table with discrete value pairs of zero positions and temperatures, or of zero positions and temperature-dependent measured values. The stored characteristic curve represents for the vertical axis of the rotating laser a correlation between the temperature and the temperature-dependent measured value and the zero position of the inclination sensor. The inclination angle that corresponds to the defined state of the vertical axis is defined as the zero position. From the characteristic curve, one can read a zero position for every temperature from the approved operating temperature range.
Preferably, the temperature or the temperature-dependent measured variable of the rotating laser is measured, the zero position associated with the temperature or measured value is determined from the characteristic curve, and the vertical axis is oriented in the state defined by the zero position. By means of the temperature measurement, one can increase the device accuracy of the rotating laser, since the influence of the temperature on the device accuracy of the rotating laser is reduced.
In a particularly preferred manner, the temperature of the rotating laser is measured by means of an inclination sensor, which comprises a housing that is filled with a liquid and a gas bubble, a light source and at least one photo detector. The measurement of the temperature of the rotating laser by means of the inclination sensor of the leveling unit has the advantage that the temperature is measured exactly at the location in the device housing of the rotating laser that is relevant for orienting the vertical axis. In addition, no additional sensor element is required for temperature measurement, so that the equipment cost for the temperature measurement is reduced.
In a particularly preferred manner, an additional characteristic curve of temperatures and bubble lengths of the gas bubble is stored, the bubble length of the gas bubble is measured using the light source and the photo detector of the inclination sensor, and the temperature associated with the measured bubble length is determined using the additional characteristic curve. The gas bubble of the inclination sensor has a bubble length that is temperature-dependent and is thus suitable as a measured variable for the temperature. The bubble length can be measured using the light source and the photo detector of the inclination sensor. For the temperature measurement, no additional sensor element is required; the temperature is measured solely using the components of the inclination sensor.
In a preferred manner, a correction angle θ is calculated from the measurement distance Dv, the first height offset H1 and the second height offset H2, and the correction angle θ is stored as the new zero position for orienting the vertical axis in the defined vertical state when the difference Δ is greater than the maximum difference Δmax. The measurement distance between the rotating laser and the laser receiver was determined as a first distance, as a second distance or as an averaged distance, and is required for calibrating the vertical axis. If the difference Δ between the first and second control points is greater than the maximum difference Δmax defined by the device manufacturer, the rotating laser does not meet the indicated device accuracy and the vertical axis must be calibrated. The correction angle θ may be calculated according to the formula tan(θ)=(H1−H2)/2Dv.
In a particularly preferred manner, the calibrated vertical axis is checked in an additional check loop, wherein the vertical state of the vertical axis is defined by the new zero position. The device axes of the rotating laser (first and second horizontal axes and vertical axis) are oriented by means of the leveling device in their respective defined state and the method for checking the vertical axis is carried out. The distance between the first control point, which is determined in the first angular position, and the second control point, which is determined in the second angular position, is calculated as difference Δ and compared against the maximum difference Δmax. When the difference Δ is less than the maximum difference Δmax, the rotating laser meets the specified accuracy. In the event that the difference Δ is greater than the maximum difference Δmax or equal to the maximum difference Δmax, an adjustment of the rotating laser is necessary.
Embodiments of the invention are described below using the drawing. It is not intended to necessarily depict the embodiments to scale; rather, the drawing, where useful for explanation's sake, is made in a schematic and/or slightly distorted form. One shall thereby take into account that diverse modifications and changes pertaining to the form and detail of a design may be undertaken, without departing from the general idea of the invention. The general idea of the invention is not restricted to the exact form or detail of the preferred design shown and described below, or restricted to a subject matter that would be restricted in comparison to the subject matter claimed in the claims. In regard to provided measurement ranges, values lying within the mentioned limits shall be disclosed as limit values and be arbitrarily usable and claimable. For the sake of simplicity, the same reference signs are used below for identical or similar parts, or parts with identical or similar functions.